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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 739 records · Page 41

High energy density aluminum-oxygen cell

An alternative to a secondary battery as the power source for vehicle propulsion is a fuel cell. An example of this is the metal-air fuel cell using metals such as aluminum, zinc, or iron. Aluminum is a particularly attractive candidate, having high energy and power densities, being environmentally acceptable, and having a large, established industrial base for production and distribution. An aluminum-oxygen system is currently under development for a UUV test vehicle, and recent work has focussed upon low corrosion aluminum alloys and an electrolyte management system for processing the by-products of the energy-producing reactions. This paper summarizes the progress made in both areas. Anode materials capable of providing high utilization factors over current densities ranging from S to 150 mA/sq cm have been identified. These materials are essential to realizing an acceptable mission life for the UUV. With respect to the electrolyte management system, a filter/precipitator unit has been successfully operated for over 250 hours in a large scale, half-cell system.

Rudd, E. J.↗

An Experimental Investigation of the Effects of Charging on the International Space Station

An experimental investigation has been undertaken to determine the effects associated with operating the International Space Station (ISS) without a Plasma Contactor Unit (PCU). The role of the PCU is to maintain the potential of the ISS to within 40 volts of the ambient plasma potential. In the event of a PCU failure, ISS structure may charge to - 160 volts with respect to the Low Earth Orbit (LEO) plasma, due to the use of high voltage photovoltaic solar arrays. Operation without a PCU will result in the charging of the oxide layers on anodized aluminum components facing into the RAM direction. In this investigation, arcs were observed as a result of anodized materials charging in a plasma environment. Actual ISS materials were used in the investigation. The materials included meteoroid and debris shield samples, as well as components from the Extravehicular Mobility Unit (EMU). Results show that the occurrence of arcs was dependent on several factors including material composition and applied voltage. The breakdown thresholds for the materials tested will be shown, as well as the voltage and current waveforms during an arc event. The damage resulting from an arc will also be described. In addition, a description of associated operational hazards resulting from arcing on the spacecraft will be provided.

Schneider, Todd↗

Space-based bacterial production of hydrogen

This paper deals with the electrochemical production of hydrogen by depolarizing the oxygen evolution reaction using human feces and urine, which contains 30-40% bacteria and yeast. The electroactivity of graphite, tungsten carbide, perovskite and RuO2-coated Ebonex (Ti4O7) as anode materials are compared. The scale-up of the process in a laboratory-scale three-dimensional packed bed cell is discussed.

NASA Discipline Life Support Systems↗

Carbon Nanotube Anodes Being Evaluated for Lithium Ion Batteries

The NASA Glenn Research Center is evaluating the use of carbon nanotubes as anode materials for thin-film lithium-ion (Li) batteries. The motivation for this work lies in the fact that, in contrast to carbon black, directed structured nanotubes and nanofibers offer a superior intercalation media for Li-ion batteries. Carbon lamellas in carbon blacks are circumferentially oriented and block much of the particle interior, rendering much of the matrix useless as intercalation material. Nanofibers, on the other hand, can be grown so as to provide 100-percent accessibility of the entire carbon structure to intercalation. These tubes can be visualized as "rolled-up" sheets of carbon hexagons (see the following figure). One tube is approximately 1/10,000th the diameter of a human hair. In addition, the high accessibility of the structure confers a high mobility to ion-exchange processes, a fundamental for the batteries to respond dynamically because of intercalation.

Raffaelle, Ryne P.↗

Visible light to electrical energy conversion using photoelectrochemical cells

Sustained conversion of low energy visible or near i.r. light (>1.25 eV) to electrical energy has been obtained using wet photoelectrochemical cells where there are no net chemical changes in the system. Stabilization of n-type semi-conductor anodes of CdS, CdSe, CdTe, GaP, GaAs and InP to photoanodic dissolution is achieved by employing selected alkaline solutions of Na.sub.2 S, Na.sub.2 S/S, Na.sub.2 Se, Na.sub.2 Se/Se, Na.sub.2 Te and Na.sub.2 Te/Te as the electrolyte. The oxidation of (poly) sulfide, (poly)selenide or (poly)telluride species occurs at the irradiated anode, and reduction of polysulfide, polyselenide or polytelluride species occurs at the dark Pt cathode of the photoelectrochemical cell. Optical to electrical energy conversion efficiencies approaching 15% at selected frequencies have been observed in some cells. The wavelength for the onset of photocurrent corresponds to the band gap of the particular anode material used in the cell.

Wrighton, Mark S.↗

Mesoporous Silicon-Based Anodes

For high-capacity, high-performance lithium-ion batteries. A new high-capacity anode composite based on mesoporous silicon is being developed. With a structure that resembles a pseudo one-dimensional phase, the active anode material will accommodate significant volume changes expected upon alloying and dealloying with lithium (Li).

Peramunage, Dharmasena↗

Development of Electrolytic Oxygen Recovery System for Advanced Life Support

The oxygen (O2) recovery system for the International Space Station (ISS) can recover approximately 50 percent of O2 from metabolic carbon dioxide (CO2). Increasing the O2 recovery rate and closing the open loop for future long duration crewed missions in space beyond Low Earth Orbit (LEO) is essential. There are several developmental efforts underway to increase the recovery rate. However, most of these technologies result in a complex, heavy, and power consuming system. The desired exploration O2 recovery system would be reliable and efficient with maximum O2 recovery. Marshall Space Flight Center (MSFC) is currently investigating an electrolytic O2 recovery approach that will increase the O2 recovery to greater than 70 percent as well as lowering the complexity, mass, and power consumption than most other technologies currently under development. The electrolytic O2 recovery system consists of a Microfluidic Electrochemical Reactor (MFECR) that is based on the electrochemical reduction of CO2 to O2 and ethylene (C2H4) using water (H2O) as precursor and operates at standard condition with a theoretical recovery rate of 73 percent. In 2016, NASA’s Game Changing Development Program awarded the University of Texas Arlington (UTA) a grant to initiate the development of the MFECR. Since 2019, MSFC and UTA have been collaborating with the current goals of increasing the O2 recovery efficiency, advancing the technology readiness to a Technology Readiness Level (TRL) 4, and maturing the system to process CO2 of one crew-member. Based on the results from UTA’s initial efforts, the following were identified as key areas of improvement in order to maximize O2 recovery for the system: further development of the anode material and cathode catalyst, model-based cell design optimization, and the addition of a separation system and fuel cell. This paper will present the current developmental efforts of the electrolytic system including MFECR design and overall system enhancements as well as results from single cell stack testing.

Brittany R Brown↗

The electrochemical reactions of pure In with Li and Na: anomalous electrolyte decomposition, benefits of FEC additive, phase transitions and electrode performance

Indium thin films are evaluated as an anode material for Li-ion and Na-ion batteries (theoretical capacities of 1012 mAh g-1 for Li and 467 mAh g-1 for Na). The native surface oxides are responsible for the anomalous electrolyte decomposition during the first cycle while oxidized In species are found to be responsible for the electrolyte decomposition during the subsequent cycles. The presence of 5wt% FEC electrolyte additive suppresses the occurrence of the anomalous electrolyte decomposition during the first cycle but is not sufficient to prevent the decomposition upon further cycling from 0 to 2 V. Prevention of the anomalous decomposition can be achieved by restricting the charge cut-off, for instance at 1.1 V, or by using larger amounts of FEC. The In films show moderately good capacity retention with storage capacities when cycled with Li (950 mAh g-1) but significantly less when cycled with Na (125 mAh g-1). XRD data reveal that several known Li-In phases (i.e LiIn, Li3In2, LiIn2 and Li13In3) form during the electrochemical reaction. In contrast, the reaction with Na is severely limited. The largest amount of inserted Na is evidenced for cells short-circuited 40 hrs at 65C, for which the XRD data show the coexistence of NaIn, In, and an unknown phase. During cycling, mechanical degradation due to repeated expansion/shrinkage, evidenced by SEM, coupled with SEI formation is the primary source of the capacity fade. Finally, we show that the In thin films exhibit very high rate capability for both Li (100 C) and Na (30 C).

Hawks, Samantha A↗

Electroactive compositions with poly(arylene oxide) and stabilized lithium metal particles

An electroactive composition includes an anodic material; a poly(arylene oxide); and stabilized lithium metal particles; where the stabilized lithium metal particles have a size less than about 200 .mu.m in diameter, are coated with a lithium salt, are present in an amount of about 0.1 wt % to about 5 wt %, and are dispersed throughout the composition. Lithium secondary batteries including the electroactive composition along with methods of making the electroactive composition are also discussed.

25 ENERGY STORAGE↗

Metal hydride compositions and lithium ion batteries

Heterogeneous metal hydride (MH) compositions comprising a main region comprising a first metal hydride and a secondary region comprising one or more additional components selected from the group consisting of second metal hydrides, metals, metal alloys and further metal compounds are suitable as anode materials for lithium ion cells. The first metal hydride is for example MgH.sub.2. Methods for preparing the composition include coating, mechanical grinding, sintering, heat treatment and quenching techniques.

25 ENERGY STORAGE↗

Nanoporous tin powder for energy applications

A nanoporous tin is disclose, along with a method of fabrication thereof, the tin having a hierarchical nanoporous and mesoporous ligament morphology that exhibits long-term cyclability, particularly when used as anode material in Li-ion. One embodiment of the present technology is a fabrication method to directly produce nanoporous tin in powder form, rather than a monolithic piece of nanoporous metal, so that the NP-Sn powder can be directly integrated into composite electrodes using commercial battery electrode processing techniques.

36 MATERIALS SCIENCE↗

Method for providing a stretchable power source and device

Disclosed in this specification is a method for providing a stretchable power source and corresponding device. The device has at least two stretchable fabrics with silver-coated fibers. Each fabric has cathodic and anodic materials, respectively, deposited between the fibers. The fibers are sealed with an elastomeric pouch having an electrolyte. The stretchable power source has substantially no change in discharge capacity when stretched from 0% strain to 100% strain.

36 MATERIALS SCIENCE↗

Prussian blue analogue electrodes without zeolitic water content

A battery is provided with a hexacyanometallate cathode. The battery cathode is made from hexacyanometallate particles overlying a current collector. The hexacyanometallate particles have the chemical formula AXM1MM2N(CN)Z.d[H2O]ZEO.e[H2O]BND, where A is a metal from Groups 1A, 2A, or 3A of the Periodic Table, where M1 and M2 are each a metal with 2+ or 3+ valance positions, where “ZEO” and “BND” indicate zeolitic and bound water, respectively, where d is 0, and e is greater than 0 and less than 8. The anode material may primarily be a material such as hard carbon, soft carbon, oxides, sulfides, nitrides, silicon, metals, or combinations thereof. The electrolyte is non-aqueous. A method is also provided for fabricating hexacyanometallate with no zeolitic water content in response to dehydration annealing at a temperature of greater than 120 degrees C. and less than 200 degrees C.

Lu, Yuhao↗

Lithiation Method for High-Energy, Long-Life Lithium-Ion Battery (L3B)

NREL is developing a low-cost method to overcome energy density and lifetime barriers faced by electric-drive vehicle batteries. Advanced anodes such as silicon are needed to enhance today's Li-ion cell energy densities and enable low cost, >200 mile range BEVs. But due to volume change during anode charge/discharge, these advanced cells presently lose more than 20% of their capacity on their first cycle. On subsequent cycles, the cells continue to degrade rapidly and only last 100-500 cycles. In comparison, the DOE BEV goal is 1000 cycles lifetime. This project goal is to enhance today's Li-ion cell energy density by 20% or more and lifetime by 50% or more by replenishing lost lithium. In addition to extending lifetime, the technology will pre-lithiate Li-starved systems to boost their initial capacity, addressing a present roadblock hindering commercialization of high-energy anode materials such as silicon. To date, NREL has more than doubled the lifetime of Si based cells supplied by Argonne National Lab's CAMP facility. The proposed device has been demonstrated in both pouch and cylindrical cells. The final design will occupy less than 5% of cell volume.

25 ENERGY STORAGE↗

Compositions including nano-particles and a nano-structured support matrix and methods of preparation as reversible high capacity anodes in energy storage systems

The present invention relates to compositions including nano-particles and a nano-structured support matrix, methods of their preparation and applications thereof. The compositions of the present invention are particularly suitable for use as anode material for lithium-ion rechargeable batteries. The nano-structured support matrix can include nanotubes, nanowires, nanorods, and mixtures thereof. The composition can further include a substrate on which the nano-structured support matrix is formed. The substrate can include a current collector material.

Kumta, Prashant N.↗

Electrochemical nanofluid or particle suspension energy conversion and storage device

An electro-chemical energy conversion and storage device includes an enclosure, a first electrode operatively connected to the enclosure, a second electrode operatively connected to the enclosure, a nanofluid or particle suspension in the enclosure, a heat transfer unit, and a circulation system for circulating the nanofluid or particle suspension to the heat transfer unit. The nanofluid includes nanoparticles plus a dielectric or ionic fluid. The particle suspension includes particles plus a dielectric or ionic fluid. A wide range of nanoparticles or particles can be used. For example the following nanoparticles or particles can be used: metal and metal alloy particles for anodic dissolution and thermal transport; hydrides as source of hydrogen ions; lithium and lithium alloys; intercalated graphite and carbon aerogel as Li source (anodic material); intercalated transition metal oxide as Li sink (cathodic material); and semiconductors for photovoltaic conversion in photo-electrochemical or hybrid electrochemical cell.

25 ENERGY STORAGE↗

Compositions including nano-particles and a nano-structured support matrix and methods of preparation as reversible high capacity anodes in energy storage systems

The present invention relates to compositions including nano-particles and a nano-structured support matrix, methods of their preparation and applications thereof. The compositions of the present invention are particularly suitable for use as anode material for lithium-ion rechargeable batteries. The nano-structured support matrix can include nanotubes, nanowires, nanorods, and mixtures thereof. The composition can further include a substrate on which the nano-structured support matrix is formed. The substrate can include a current collector material.

Kumta, Prashant Nagesh↗

Solid-state batteries and the critical role of interfaces

The Grand Challenge for the next generation of energy storage technologies is no longer the identification of electroactive cathode or anode materials thanks to extensive worldwide synthesis efforts along with theory and modeling like the Materials Project.1 Instead, the critical challenges revolve around assembling materials in the right architecture to achieve maximum performance and cell life at reasonable temperatures and pressures. Nowhere is this more critical than on the next generation of energy storage technologies revolving around all solid-state batteries. These batteries are the ultimate challenge for materials science requiring new ways to assemble multiple dissimilar materials such that: (1) interfaces are optimized to facilitate ion motion across the different compounds while (2) maintaining chemical stability and (3) simultaneously preserving the crystal structures of each phase during (4) large volume changes due to shuttling of lithium, at (5) room temperature and under (6) atmospheric pressure. To address these requirements will require insights and expertise from research fields outside the traditional lithium-ion battery community such as solid oxide fuel cells, synthesis science, barrier layers, interface formers, sintering, and mechanical properties.

25 ENERGY STORAGE↗